Hi charliegrumpies, Sorry you are so sore, probably only a physiotherapist will be able to help you, but in the meantime here is what I do.
I take ibuprofen (muscle relaxant) with a paracetemol. The two different pills, just one of each, help me.
Ice packs will contract the pain site, and bring some relief.
You could try the following exercise my physio gave me.
1. Lie on your back on your bed, perfectly straight, now bring your knees up slowly to your chest (this is not a stomach exercise, so keep your feet on the bed while bending your knees and then clasp hands around your knees and bring them to your chest.) There must be no pulling on your lower back while lifting your knees.
Hold this position for 1 minute, keeping your knees as close to your chest as you can. Let go, slowly and again slowly put your feet on the bed and let them slide down until you're lying flat.
2. Bend one leg up and bring your knee to your chest and hold for 30 seconds, slowly release and slide heel down until the leg is flat. Do the same for the other leg. Do it three times each side.
3. Most important to end this regimen, you must do the top exercise again, holding both knees to your chest for 1 minute.
Essential you put no strain on your lower back, and do everything slowly and gently.
Please if there is any pain, don't do this rather let a professional help you.